Textured ligating band and method of use of same

ABSTRACT

An elastic band for ligating tissue within a living body comprises an inner tissue engaging surface which, when in an operative position within the body, surrounds and directly contacts the tissue. At least a portion of the inner tissue engaging surface defines a plurality of discontinuities formed by one of projections and depressions. A method of ligating tissue within a living body using such a ligating band comprises the steps of positioning the elastic band, which has been stretched to increase the size of a central opening extending therethrough, adjacent to a portion of tissue to be ligated. The tissue to be ligated is then drawn through the central opening of the elastic band and the elastic band is released so that the size of the central opening decreases to grip the tissue received therein.

FIELD OF THE INVENTION

[0001] The invention relates generally to the field of tissue ligation,and more particularly to an improved ligating band and a method of useof the ligating band to ligate tissue.

BACKGROUND OF THE INVENTION

[0002] Physicians have used elastic ligating bands to treat lesions,including internal hemorrhoids and mucositis and for performingmechanical hemostasis.

[0003] The object of ligation is to position a ligating band over thetargeted lesion or blood vessel section by stretching the band beyondits undeformed diameter drawing the tissue to be ligated within the bandand then releasing the band so that it contracts, applying inwardpressure on the section of tissue caught within the band. The effect ofthe inward pressure applied by the band is to stop all circulationthrough the targeted tissue, thereby causing the tissue to die. The bodythen sloughs off the dead tissue or the dead tissue may be aspiratedinto an endoscope or a similar device.

[0004] U.S. Pat. No. 5,356,416 to Chu et al. and U.S. Pat. No. 5,398,844to Zaslavsky et al., both of which are incorporated herein by reference,describe ligating band dispensing devices including cylindrical supportsurfaces over which elastic ligating bands are stretched. Thecylindrical support surfaces are typically attached to the distal end ofan endoscope which is advanced into the body to a target area. A userthen applies suction through the endoscope to draw the tissue to beligated into the cylindrical support surface and then releases aligating band to contract around the tissue.

[0005] There are two problems inherent with the type of ligating bandstypically used with the above-described devices. The first is that thebands have a tendency to slip off the targeted tissue before the tissueis completely ligated. One reason why a ligating band may slip offtargeted tissue is because tissue contained within a ligating band iseffectively “pinched” by the ligating band, creating an outward pressureon the band. Specifically, the bulb-shaped projection of tissue whichhas been drawn under suction into the lumen of a cylindrical supportsurface is pulled away from the surrounding tissue creating tensionwithin the projection which draws the tissue of the projection backtoward the its natural position. Thus, the tissue is urged to slip outof the ligating band as the band contracts. In addition, blood and fluidwithin the body can make the surface of the targeted tissue slick,thereby decreasing the coefficient of friction between the ligating bandand the targeted tissue. Also, if the targeted tissue is an active bloodvessel the “pulsing” effect of blood moving through the vessel can causethe ligating band to slip off of the targeted tissue.

[0006] A second problem with current ligating bands is that the bandsare not adjustable once they have been dispensed from the ligating banddispenser. Therefore, if a band is improperly placed around a section oftissue, or if the physician placing the ligating band should wish todraw more tissue within the band, there is no effective way to adjustthe band.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to an elastic band for ligatingtissue within a living body comprising an inner tissue engaging surfacewhich, when in an operative position within the body, surrounds anddirectly contacts the tissue. At least a portion of the inner tissueengaging surface defines a plurality of discontinuities formed by one ofprojections and depressions. A method of ligating tissue within a livingbody using such a ligating band comprises the steps of positioning theelastic band, which has been stretched to increase the size of a centralopening extending therethrough, adjacent to a portion of tissue to beligated. The tissue to be ligated is then drawn through the centralopening of the elastic band and the elastic band is released so that thesize of the central opening decreases to grip the tissue receivedtherein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The invention will be more readily understood through thefollowing detailed description, with reference to the accompanyingdrawings, in which:

[0009]FIG. 1 is a perspective view of a first ligating band according toa embodiment of the present invention;

[0010]FIG. 2 is a perspective view of a ligating band according to asecond embodiment of the present invention;

[0011]FIG. 3 is a perspective view of a ligating band according to athird embodiment of the present invention;

[0012]FIG. 4 is a perspective view of a ligating band according to thesecond embodiment of the present invention, wherein the texturing isperpendicular to the band's centerline axis;

[0013]FIG. 5 is a perspective view of a ligating band according to thethird embodiment of the present invention, wherein the texturing isperpendicular to the band's centerline axis;

[0014]FIG. 6 is a perspective view of a ligating band according to thesecond embodiment of the present invention, wherein the texturing isangled to the band's centerline axis;

[0015]FIG. 7 is a perspective view of a ligating band according to thethird embodiment of the ligating band depicted in FIG. 3, wherein thetexturing is angled to the band's centerline axis;

[0016]FIG. 8 is a perspective view of an alternate embodiment of theligating band depicted in FIG. 2, wherein the texturing is parallel tothe band's centerline axis, and showing manipulation apertures;

[0017]FIG. 9 is a perspective view of an alternate embodiment of theligating band depicted in FIG. 3, wherein the texturing is comprised ofsecuring prongs, and showing manipulating apertures;

[0018]FIG. 10 is a perspective view of an alternate embodiment of theligating band depicted in FIG. 9, wherein the securing prongs areconfigured as injection prongs;

[0019]FIG. 11 shows a side view of a blood vessel drawn into a devicefor applying ligating bands;

[0020]FIG. 12 shows a side view of a blood vessel with an elasticligating band received thereon;

[0021]FIG. 13 shows a side view of a blood vessel received within adevice for applying ligating bands wherein the elastic ligating band hasbeen reopened on the blood vessel to adjust its position;

[0022]FIG. 14 shows a side view of the blood vessel of FIG. 13, whereinthe elastic ligating band has been released;

[0023]FIG. 15 shows a side view of a ligating band of FIG. 9, wherein aligating band spreading device is being used to stretch the ligatingband while a mechanical gripping device is used to draw tissue throughthe central opening in the ligating band;

[0024]FIG. 16 shows a side view of the ligating band of FIG. 9 whereinthe ligating band spreading device has been inserted through a centralchannel formed through an endoscope or other insertion device;

[0025]FIG. 17 shows a side view of a distal end of an alternate ligatingband dispensing device specifically adapted for use with texturedligating bands.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026] As illustrated in FIG. 1, a ligating band 1 is preferably formedas a ring with an inner surface 2, an outer surface 4, a first sidesurface 6, and a second side surface 8. Of course, those skilled in theart will understand that during manipulation, the ligating band 1 may beintentionally or accidentally twisted so that any of the surfaces 4, 6and 8 becomes the inner surface 2. Thus, in the ligating band 1according to the first embodiment of the invention includes texturing 10which covers all surfaces of the ligating band 1.

[0027] The ligating band 1 according to the first embodiment has across-section which is substantially rectangular. That is, the ligatingband 1 is formed as a portion of a cylinder. Those skilled in the artwill recognize that one or more of surfaces 2, 4, 6, or 8 may be roundedreducing the distinction between the various surfaces. However, thisdistinction between the various surfaces is unimportant so long as thesurface of the ligating band 1 which is in contact with the tissue to beligated includes texturing as described herein.

[0028] As shown in FIG. 1, the texturing 10 is comprised of a pattern ofraised bumps which are formed as cylindrical stems 12 and hemisphericalcaps 14. Alternate forms of texturing 10 can employ one or more of avariety of different shapes, including raised elongated members 16 asshown in FIG. 4, securing prongs 24 as shown in FIG. 9, or indentations(not shown) in the inner surface 2 of the ligating band 1. On anysurface 2, 4, 6 or 8 to which the texturing 10 is applied, the texturing10 is preferably evenly distributed.

[0029] The texturing 10 may preferably be applied to the ligating band 1via a molding process, thereby making the texturing 10 an integral partof the structure of the ligating band 1. Preferably, the texturing 10and the ligating band 1 are formed from latex or a synthetic equivalentthereof, such as polyisoprene. The ID (inner diameter) of the ligatingbands 1 may preferably be between 0.06 and 0.10 inches and is morepreferably approximately 0.07 inches. The OD (outer diameter) of theligating bands is preferably between 0.20 and 0.24 inches, while thebands may preferably be approximately 0.08 inches thick in a directionsubstantially parallel to a central axis of the ligating bands 1. Ofcourse, those skilled in the art will recognize that such a ligatingband may easily be twisted so that the ID surface becomes the ODsurface, etc. and that it may therefore be preferable to make thethickness of the band in each direction between 0.06 to 0.18 inches.

[0030] The texturing 10 is applied to the ligating band 1 so that theraised bumps on a first side 18 of the inner surface 2 and the raisedbumps on a second side 20 thereof combine to form an interlockingpattern. By interlocking those skilled in the art will understand thatthe raised bumps on both the first side 18 and the second side 20 holdthe tissue to be ligated by the ligating band 1 more securely in placewhen the ligating band 1 applies inward pressure on said tissue with thebumps from one side forcing the tissue into a gap between the bumps onthe other side. Thus, as shown in FIG. 4, raised elongated members 16 onthe first side 18 of the inner surface 2 may also form an interlockingpattern with respect to the second side 20 of the inner surface 2.

[0031] As shown in FIG. 8, an ligating band 1 according to the presentinvention may also include one or more manipulating apertures 22. Ifmanipulating apertures 22 are used in conjunction with an ligating band1, it is preferable to have at least three manipulating apertures 22but, may have four or more. The purpose of the manipulating apertures 22is to allow the physician placing the ligating band of the presentinvention to control the proper placement of the ligating band on thetissue to be ligated by inserting tines 42 of a ligating band spreader38 into the apertures 22 and, by spreading the tines 42 apart,increasing the interior diameter d of the ligating band 1 so that theposition of the ligating band 1 on the tissue to be ligated may beadjusted to allow an additional amount of tissue to be drawn up throughthe interior diameter d of the ligating band 1. Alternatively, thephysician may use such a manipulating instrument 38 with an ligatingband 1 including apertures 22 to originally place ligating bands ontissue to be ligated. That is, the physician may place an ligating band1 including apertures 22 on the manipulating device, spread the tines 42to increase the diameter d and manually draw tissue through the centralopening in the ligating band 1. The physician may then release theligating band 1 to ligate the tissue.

[0032] With reference to FIG. 1, although it is preferable to havetexturing 10 on all surfaces 2, 4, 6 and 8 of the ligating band 1, it isnot necessarily required so long as the user ensures that the surfaceincluding the texturing 10 remains, through the placement procedure,positioned so that it contacts the surface to be ligated. In use, thetissue to be ligated is drawn up within the interior diameter d of theligating band 1. Thus, only texturing 10 placed on the surfacepositioned at inner surface 2 is designed to come in contact with thetissue to be ligated. FIG. 2 depicts an ligating band 1 according to thepresent invention wherein texturing 10 is provided only on the innersurface 2 and the outer surface 4, while FIG. 3 depicts an ligating band1 according to the present invention wherein texturing 10 is providedonly on the inner surface 2.

[0033] However, it is preferred that texturing 10 be provided on each ofsurfaces 4, 6 and 8 in addition to inner surface 2 as the ligating band1 may “roll” after during the dispensing procedure or after beingdispensed onto the tissue to be ligated. Thus, a physician cannot becertain that the ligating band 1 will not ultimately be turned “insideout” on the tissue to be ligated such that outer surface 4, for example,comes in contact with the tissue to be ligated rather than the innersurface 2.

[0034] With references to FIGS. 4 and 5, the texturing 10 may becomprised of raised elongated members 16 and placed in such a mannerthat the raised elongated members 16 are aligned perpendicular to thelongitudinal centerline Cl of the ligating band 1. Alternately, theraised elongated members 16 may be placed at an angle, preferablybetween 30° and 60°, to the longitudinal centerline Cl of the ligatingband 1, as shown in FIGS. 6 and 7. Alternatively, the raised elongatedmembers 16 may be placed perpendicular to the longitudinal centerline Clof the ligating band 1, as shown in FIG. 8.

[0035] In FIG. 9, securing prongs 24 are used to provide texturing 10 tothe inner surface 2 of the ligating band 1. The securing prongs 24perform the same function as either the other types of texturing 10previously described; that is, the securing prongs 24 increase theresistance of the ligating band 1 to any forces acting to dislodge itfrom the tissue to be ligated.

[0036] The securing prongs 24 may alternately be configured as injectionprongs 26, as shown in FIG. 10. After tissue to be ligated has beendrawn within the interior diameter d of the ligating band 1, theligating band 1 is allowed to return to its undeformed state, applyinginward pressure on the tissue. By employing injection prongs 26, notonly does the ligating band 1 depicted in FIG. 10 securely hold thetissue to be ligated in place, but it also pierces the tissue with theinjection prongs 26, thereby injecting a fluid held in an interiorreservoir 28 into the tissue. The fluid is injected as the return of theligating band 1 to its undeformed state compresses the reservoir 28.Those skilled in the art will recognize that this fluid may be asclerotherapy agent, a healing agent or any other desired medicinalfluid. Alternatively, the fluid may be coated on an area F at the tips30 of the injection prongs 26, so that the fluid F would be injectedinto the tissue after the tissue to be ligated has been drawn within theinterior diameter d of the ligating band 1 and the ligating band 1 hasbeen allowed to return to its undeformed state.

[0037] Alternately, injection prongs 26 may be used to transmit RFenergy into the section of tissue directly beneath the tissue to beligated. To achieve this, the structure illustrated as the reservoir 28,is replaced by a similarly shaped and situated electrically conductivemember which, after the ligating band 1 has been positioned on thetissue, may be coupled to a source of RF energy via apertures 22 tocauterize the surrounding tissue. Those skilled in the art willunderstand that the electrically conductive material may be in the formof a spring or other expandable shape to allow the structure to expandand contract when the ligating band is stretched or released.

[0038] In use, as shown in FIGS. 11-16, in use a physician first loadsthe ligating band 1 onto the distal end of a ligating band dispenser 32,such as the ligating dispenser described in U.S. Pat. No. 5,356,416, sothat the interior diameter d of the ligating band 1 is substantiallygreater that its natural, pre-deformed interior diameter d.

[0039] Next the physician positions a distal aperture 34 of the ligatingband dispenser 32 adjacent to a first section of tissue T1. The firstsection T1 is then drawn into the distal aperture 34, preferably undersuction. Alternatively, the first section of tissue T1 may be drawnwithin the distal aperture 34 by mechanical means, such as a forceps,jaws, clamp, or the like (not shown). The physician then triggers theligating band dispenser 32 to release one or more ligating bands 1 overthe targeted tissue T1.

[0040] As seen in FIG. 12, when the ligating band 1 has been dispensedfrom the ligating band dispenser 32, the interior diameter d of theligating band 1 suddenly decreases as the ligating band 1 seeks toreturn to its predeformed state. As the interior diameter d decreases,the texturing 10 on the inner surface 2 of the ligating band 1 engages aportion 36 of the first section of tissue 33 and exerts inward pressureon the tissue 36. The pressure on the tissue 39 stops all circulationthrough the targeted tissue T1, thereby causing the portion 36 to die.The body then sloughs off the dead tissue 36. Alternatively, the deadtissue 36 may be removed by mechanical means and aspirated into anendoscope, the ligating band dispenser 32, or a similar device.

[0041] While the texturing 10 on the inner surface 2 of the ligatingband 1 is exerting inward pressure on the tissue 36, the texturing 10restricts the movement of the ligating band 1 over the tissue 36. Thus,the ligating band 1 of the present invention is less likely than priorart ligating bands to be displaced from the targeted tissue 36 inresponse to outward pressures caused by the “pinching” of the targetedtissue 33 or by the movement of blood or other fluid through thetargeted tissue T1. In addition, when the texturing 10 on the innersurface 2 of the ligating band 1 is exerting inward pressure on thetissue 36, it is preferable that the texturing 10 on the first side 18of the inner surface 2 remotely engages the texturing 10 on the secondside 20 of the inner surface 2 through the portion 36 of tissue to forman interlocking pattern. By forming such an interlocking pattern, thetexturing 10 more effectively restricts the movement of the ligatingband 1 relative to the tissue 36.

[0042] As discussed previously, the optional manipulation apertures 22provide the physician with the ability to place the ligating band 1directly over the targeted tissue 36 and then decrease the interiordiameter d until the texturing 10 on the inner surface 2 of the ligatingband 1 engages and exerts inward pressure against the tissue 36. Toposition the ligating band 1, the physician loads the ligating band 1onto a ligating band spreader 38 by inserting each of the tines 42 intoone of the manipulation apertures 22. Next, the physician manipulatesthe ligating band spreader 38 to increase the interior diameter d of theligating band 1, and positions the ligating band 1 adjacent to the firstsection of tissue T1. A portion of the tissue is then drawn through theligating band 1 (using a clamping device 40 for example), and thephysician manipulates the ligating band spreader 38 to decrease theinterior diameter d of the ligating band 1 until the texturing 10engages the tissue 36.

[0043] By manipulating the ligating band spreader 38, the physician maynot only position the ligating band 1 over the tissue 36, but may alsosubsequently wholly or partially disengage the ligating band 1 from thetissue 36 to allow the physician to reposition the ligating band 1relative to the tissue 36. The physician may use the ligating bandspreader 38 whether the ligating band 1 was initially placed over thetissue 33 using a ligating band spreader 38 or using a ligating banddispenser 32.

[0044] Finally, FIG. 17 shows the distal end 50 of an alternate ligatingband dispensing device including a ligating band supporting structure 52which has a diameter which decreases from a maximum diameter at aproximal end 54 to a minimum diameter at a distal end 58. Thus, theligating band supporting structure 52 may be formed as a portion of acone. As shown in FIG. 17, the proximal end 54 is received within asleeve 60 which forms an abutting surface 62 adjacent to the outersurface of the proximal end 54 so that, when a plurality of ligatingbands 4 are received on the ligating band supporting structure 52, aproximal most ligating band 4 may not move proximally past the abuttingsurface 62. The ligating band supporting structure 52 is coupled withinthe distal end 50 so that the ligating band supporting structure 52 maybe moved proximally relative to the abutting surface 62, for example bybeing screwed into the sleeve 60 by rotation about the central axis C inthe direction of arrow A. Thus, as the ligating band supportingstructure 52 is moved into the sleeve 60, the proximal most ligatingband 4 abuts the abutting surface 62 and pushes the more distal ligatingbands 4 toward the distal end 58 until they are dispensed therefromone-by-one. Eventually, when the distal end 58 is drawn proximally pastthe abutting surface 62, the proximal-most ligating band 4 is dispensedfrom the ligating band supporting structure 52. Thus, as the forceurging the ligating bands 4 off the ligating band supporting structure52 is applied around the entire circumference of the ligating bands 4,the increased frictional forces associated with the textured ligatingbands according to the present invention may more easily be overcome.

[0045] Still other objects and advantages of the present invention willbecome readily apparent to those skilled in the art from the detaileddescription, wherein the preferred embodiment and several alternateembodiments of the invention have been shown and described. Thedescription of the preferred embodiment is simply by way of illustrationof the best mode contemplated for carrying out the invention. As will berealized, the invention is capable of other and different embodiments,and its several details are capable of modification in various respects,all without departing from the invention. Accordingly, the drawings anddescriptions are to be regarded as illustrative in nature, and not asrestrictive of the invention which is to be limited only by the claimsappended hereto.

What is claimed is:
 1. An elastic band for ligating tissue within aliving body, comprising: a ring formed of elastomeric material, the ringincluding an inner tissue engaging surface which, when in an operativeposition within the body, surrounds and directly contacts the tissue;and a plurality of projections disposed on and integrally formed withthe inner surface, at least a portion of each of the plurality ofprojections being formed of the elastomeric material and each of theprojections including a substantially cylindrical stem and asubstantially hemispherical cap.
 2. The elastic band according to claim1, wherein the projections are arranged in a predetermined pattern sothat each of the projections faces across a central opening of the ringto a space between projections formed on a corresponding oppositeportion of the inner surface.
 3. The elastic band according to claim 1,further comprising at least one tissue piercing end for penetrating thetissue.
 4. The elastic band according to claim 1 further comprising anelectrically conductive material extending from at least one of theprojections to a contact point accessible from a proximal side of theelastic band.
 5. An elastic band for ligating tissue within a livingbody, comprising: an inner tissue engaging surface which, when in anoperative position within the body, completely surrounds and directlycontacts the tissue; and a second surface of the elastic band which,when in an operative position, is accessible to a spreading instrument,the second surface including a plurality of manipulation ports, each ofthe manipulation ports being sized to receive a tine of the spreadinginstrument therein.
 6. The elastic band according to claim 5, furthercomprising a plurality of projections disposed on the inner tissueengaging surface.
 7. The elastic band according to claim 6, wherein theprojections are arranged so that each of the projections extends into acentral opening of the elastic band toward a space between projectionson an opposite side of the central opening.
 8. The elastic bandaccording to claim 6, wherein at least one of the projections includes acylindrical stem projecting away from the first surface to ahemispherical end.
 9. The elastic band according to claim 6, wherein theinner tissue engaging surface is substantially circular and each of theprojections extends circumferentially about a portion of the innertissue engaging surface, a length of each projection in thecircumferential direction being substantially greater than a length ofeach projection in a direction substantially perpendicular to thecircumferential direction.
 10. The elastic band according to claim 6,wherein the elastic band is substantially in the shape of a ring anddefines a central axis extending through the central opening and whereinthe projections extend around the first surface substantially parallelto one another at a predetermined angle with respect to the centralaxis.
 11. The elastic band according to claim 6, wherein at least one ofthe projections includes a tissue piercing end.
 12. The elastic bandaccording to claim 6, further comprising an electrically conductivematerial extending from at least one of the projections to a contactpoint accessible from a proximal side of the elastic band.
 13. A methodof ligating tissue with a living body, comprising: positioning anelastic band which has been stretched to increase the size of a centralopening extending therethrough adjacent to a portion of tissue to beligated, the elastic band including a ring formed of elastomericmaterial, the ring including an inner tissue engaging surface which,when in an operative position within the body, surrounds and directlycontacts the tissue, and the elastic band including a plurality ofprojections disposed on and integrally formed with the inner surface, atleast a portion of each of the plurality of projections being formed ofthe elastomeric material and each of the projections including asubstantially cylindrical stem and a substantially hemispherical cap;drawing a portion of tissue to be ligated through the central opening ofthe elastic band; and releasing the elastic band so that the size of thecentral opening decreases to grip the tissue received therein.
 14. Themethod according to claim 13, wherein the projections are arranged in apredetermined pattern so that each of the projections faces across acentral opening of the ring to a space between projections formed on acorresponding opposite portion of the inner surface.
 15. The methodaccording to claim 13, wherein the projections include least one tissuepiercing end for penetrating the tissue.
 16. The method according toclaim 13, wherein the elastic band further includes an electricallyconductive material extending from at least one of the projections to acontact point accessible from a proximal side of the elastic band,further comprising: applying RF energy to the tissue through theelectrically conductive material.